5种乳酸菌及其灭活态体外抗氧化能力的比较研究

Comparative Studies on Antioxidant Activity in Vitro of Five Species of Active and Inactived Lactic Acid Bacterial

以总抗氧化活性(T-AOC)、总超氧化物歧化酶(T-SOD)活力、羟自由基清除率(OH^-·)、超氧阴离子清除率(O2^-·)、还原活性为测定指标,对5株乳酸菌灭活前后发酵上清液、完整细胞悬液、胞内提取物的抗氧化能力进行比较研究,并筛出抗氧化能力相对较强的3株乳酸菌进行复配。结果表明:5种乳酸菌灭活前后的发酵上清液、完整细胞悬液、胞内提取物具有不同的抗氧化能力,其中嗜酸乳杆菌灭活前和灭活后的发酵上清液的总抗氧化活性最好,分别为45.9、35.0 U/mL。菊糖芽孢乳杆菌未灭活的发酵上清液的超氧阴离子自由基清除率较强为21.03%。嗜热链球菌的灭活胞内提取物的总超氧化物歧化酶活力最强为456.7 U/mL,其未灭活的胞内提取物的羟自由基清除率最强为79.26%。唾液乳杆菌的灭活发酵上清液的还原活性最强。复配结果表明,灭活完整细胞悬液的超氧阴离子清除率(O2^-·)较单一菌株强;菊糖芽孢乳杆菌和嗜酸乳杆菌复配后灭活完整细胞悬液的羟自由基清除率(OH^-·)最强,为82.40%;而菌株复配后的总抗氧化活性(T-AOC)、总超氧化物歧化酶(T-SOD)活力与单菌差异不显著。不同乳酸菌菌株的抗氧化能力存在差异,且其发挥抗氧化作用的活性物质存在的部位也因菌株不同而具有较大的差异性。

The antioxidant activities of fermentation supernatant,intact cell suspension and intracellular extract of 5 strains of lactic acid bacteria before and after inactivation were compared by total antioxidant activity(T-AOC),total superoxide dismutase(T-SOD)activity,hydroxyl radical scavenging rate(OH^-·),superoxide anion scavenging rate(O2^-·)and reducing activity. 3 strains of lactic acid bacteria with relatively strong antioxidant capacity were screened for compounding. The results showed that the fermentation supernatants,intact cell suspensions and intracellular extracts of the five lactic acid bacteria before and after inactivation had different antioxidant capacity. The fermentation supernatants before and after inactivation of Lactobacillus acidophilus had highest total antioxidant activity,45.9 U/mL and 35.0 U/mL,respectively. The scavenging ability of superoxide anion free radical in the non-inactivated fermentation supernatant of Sporolactobacillus inulinus was strong,which was 21.03%. The inactivated intracellular extract of Streptococcus thermophilus had the strongest total superoxide dismutase activity of 456.7 U/mL,and its non-inactivated intracellular extract had the higest hydroxyl radical scavenging rate of 79.26%. The inactivated fermentation supernatant of Lactobacillus salivarius had the strongest reducing activity. The combination of Lactobacillus hesporum,Lactobacillus salivarius and Lactobacillus acidophilus showed that the superoxide anion scavenging rate(O2^-·)of inactivated intact cell suspension was higher than that of the single strain;The hydroxyl radical scavenging rate(OH^-·)of the inactivated intact cell suspension after the combination of Bacillus and Lactobacillus acidophilus was the strongest,which was 82.40%;The total antioxidant activity(T-AOC)and total superoxide dismutase(T-SOD)activity of the mixed strains were not significantly different from those of the single bacteria. Different fractions from lactic acid bacteria have different antioxidant activities in vitro. Therefore,lactic acid bacteria from difference resources,concentrations and excretion places also exhibited different antioxidant activities.